A steel tank contains carbon dioxide at a temperature of 300 K and a pressure of 5.0 MPa
CHEMISTRY · Multi-part · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures
Problem
A steel tank contains carbon dioxide at a temperature of 300 K and a pressure of 5.0 MPa. Measurements show that the quantity PV for the gas is smaller than the value predicted by the ideal-gas law for the same n and T.
(a) Identify the specific assumption or assumptions of the ideal-gas model whose breakdown most directly explains the observed difference between the measured and predicted PV values. Provide qualitative reasoning based on molecular behavior.
(b) If the volume of the tank were slowly increased while the temperature remained at 300 K, describe qualitatively how the actual pressure–volume curve for the carbon dioxide would compare with the curve predicted by the ideal-gas law. Explain your reasoning.
(c) The tank is now cooled toward 200 K while its volume stays fixed. Explain how this change in temperature affects the validity of the ideal-gas model for the carbon dioxide and predict the direction of any additional deviation from ideal behavior.